Mycobacterium Terrae Complex Research Articles

The genomic heterogeneity among Mycobacterium terrae complex displayed by sequencing of 16S rRNA and hsp 65 genes.

The species identification within Mycobacterium terrae complex has been known to be very difficult. In this study, the genomic diversity of M. terrae complex with eighteen clinical isolates, which were initially identified as M. terrae complex by phenotypic method, was investigated, including that of three type strains (M. terrae, M. nonchromogenicum, and M. triviale ). 16S rRNA and 65-kDa heat shock protein (hsp 65) gene sequences of mycobacteria were determined and aligned with eleven other references for the comparison using similarity search against the GenBank and Ribosomal Database Project II (RDP) databases. 16S rRNA and hsp 65 genes of M. terrae complex showed genomic heterogeneity. Amongst the eighteen clinical isolates, nine were identified as M. nonchromogenicum, eight as M. terrae, one as M. mucogenicum with the molecular characteristic of rapid growth. M. nonchromogenicum could be subdivided into three subgroups, while M. terrae could be subdivided into two subgroups using a 5 bp criterion (>1% difference). Seven isolates in two subgroups of M. nonchromogenicum were Mycobacterium sp. strain MCRO 6, which was closely related to M. nonchromogenicum. The hsp 65 gene could not differentiate one M. nonchromogenicum from M. avium or one M. terrae from M. intracellulare. The nucleotide sequence analysis of 16S rRNA and hsp 65 genes was shown to be useful in identifying the M. terrae complex, but hsp 65 was less discriminating than 16S rRNA.

A High Proportion of Novel Mycobacteria Species Identified by 16S rDNA Analysis Among Slowly Growing AccuProbe-Negative Strains in a Clinical Setting

Sequencing of the 16S ribosomal DNA (rDNA )for identification of nontuberculous mycobacteria (NTM) has contributed to the establishment of more than 35 new species during the last decade. Increasingly, NTM are accepted as potential or proven pathogens. We identified, by 16S rDNA sequence analysis, slowly growing NTM isolates negative by AccuProbe (GenProbe, San Diego, CA) that previously were identified by using conventional biochemical techniques, to determine the accuracy of reporting AccuProbenegative NTM prior to sequence-based identification. Of 82 strains, 30 were deemed novel. An attempt was made to determine the clinical importance of previously misidentified novel species. Clinical cases are described for a number of strains previously identified as Mycobacterium terrae complex, Mycobacterium scrofulaceum, and Mycobacterium avium complex. As sequence-based identification methods become more commonplace in clinical microbiology laboratories, there is a need to understand the significance of previously undescribed species, which often mimic and subsequently are identified as well-established species. Many nontuberculous mycobacteria (NTM) are ubiquitous in the environment and may colonize and occasionally cause infection in humans. Mycobacterium avium complex, Mycobacterium kansasii, and members of the Mycobacterium fortuitum complex are causative agents for most NTM infections and currently have a well-understood environmental epidemiology. 1 Other NTM species rarely cause infection,

A high proportion of novel mycobacteria species identified by 16S rDNA analysis among slowly growing AccuProbe-negative strains in a clinical setting.

Sequencing of the 16S ribosomal DNA (rDNA) for identification of nontuberculous mycobacteria (NTM) has contributed to the establishment of more than 35 new species during the last decade. Increasingly, NTM are accepted as potential or proven pathogens. We identified, by 16S rDNA sequence analysis, slowly growing NTM isolates negative by AccuProbe (GenProbe, San Diego, CA) that previously were identified by using conventional biochemical techniques, to determine the accuracy of reporting AccuProbe-negative NTM prior to sequence-based identification. Of 82 strains, 30 were deemed novel. An attempt was made to determine the clinical importance of previously misidentified novel species. Clinical cases are described for a number of strains previously identified as Mycobacterium terrae complex, Mycobacterium scrofulaceum, and Mycobacterium avium complex. As sequence-based identification methods become more commonplace in clinical microbiology laboratories, there is a need to understand the significance of previously undescribed species, which often mimic and subsequently are identified as well-established species.

Opportunistic mycobacterial granuloma in a cat associated with a member of the Mycobacterium terrae complex

An 18-month-old domestic short-haired neutered male cat presented with a nodular dermal thickening on a digit. Biopsy demonstrated pyogranulomatous inflammation with moderately frequent acid-fast bacilli. A member of the Mycobacterium terrae complex was isolated. There was no evidence of systemic involvement. Treatment was initiated with enrofloxacin, rifampicin and clarithromycin. After 2 months there was no longer any clinically apparent dermal thickening. Treatment was continued for a further 3 months using enrofloxacin and rifampicin.

Infección pulmonar por Mycobacterium terrae

Mycobacterium terrae complex encompasses three species of microbacteria that are usually saprophytic and that may occasionally cause disease in humans, particularly in joints and synovial fluid. The literature includes slightly over a dozen cases of pulmonary infection, although none has been described in Spain. We report a case of infection by M. terrae in an immunodepressed patient with no other risk factor. Microbial identification by culture was unexpected and clinical management was difficult due to the absence of an established treatment protocol.

Urinary tract infection caused by Mycobacterium terrae complex

We describe a case of recurrent urinary tract infection caused by Mycobacterium terrae complex in a patient with obstructive nephropathy. The mycobacterium was resistant to most antituberculosis drugs and despite its apparent clearance in the urine, the patient finally died of urinary sepsis caused by multiple bacterial pathogens.

Detection and identification of non-tuberculous mycobacterial infections in 6,472 tuberculosis suspected patients.

Between March 1993 and March 1994, 82 patients with infection by non-tuberculous mycobacteria (NTM) and 443 patients with tuberculosis (TB) were registered among 6,472 patients with suspected tuberculosis. Skin-test reactivity to purified protein derivative (PPD) in patients demonstrated indurations of 10-14 mm or more for the majority of patients in both groups. Most patients with NTM infection had abnormal chest roentgenograms showing sporadic infiltrations, nodular abscesses, and cavities resembling TB radiological evidence. The similarity in age range, PPD skin reaction, and radiological evidence in patients infected with NTM or Mycobacterium tuberculosis (MTB) can mislead the physician. Some NTM species were recovered more often than others. Mycobacterium fortuitum from 22 clinical specimens (26.8%); Mycobacterium gastric 19 (23.1%); and Mycobacterium terrae complex 15 (18.3%). The antimicrobial drug susceptibility tests of the isolated organisms showed that 42 (9.5%) isolates of MTB were resistant to isoniazid and 31 (7.0%) to streptomycin. a few strains (1.3%) were identified as being resistant to a combination of 3 primary drugs. These findings suggest that drug-resistant mycobacterial infections are becoming an important problem in the region.

Strains of Mycobacterium terrae complex which react with DNA probes for M. tuberculosis complex

Following a recent report that two isolates of Mycobacterium terrae complex had given positive reactions with M. tuberculosis complex DNA probes, a joint study was undertaken to determine the extent of these findings in the clinical culture collection holdings of two state health laboratories. A total of 117 M. terrae complex strains (identified by standard biochemical methods) were subjected to M. tuberculosis complex probe testing with the two then-available kits (from Syngene, Inc., and Gen-Probe, Inc.). In addition to the two original isolates first reported, two further M. terrae complex isolates were found to react with the M. tuberculosis complex probes. Two modifications of the Accuprobe (Gen-Probe, Inc.) test method were evaluated. Extension of the selection time to 8 min was the most convenient modification and rendered the M. terrae complex isolates negative when tested with the Accuprobe M. tuberculosis complex probe. However, the effects of increased selection time on the overall sensitivity of the M. tuberculosis complex probe require further study.

Chronic Tenosynovitis of the Hand Due to Mycobacterium nonchromogenicum: Use of High-Performance Liquid Chromatography for Identification of Isolates

Six cases of chronic tenosynovitis of the hand due to the Mycobacterium terrae complex were identified. All isolates from the six cases were identified as Mycobacterium nonchromogenicum by high-performance liquid chromatography and by testing for susceptibility to ofloxacin and to 5% NaCl. Ethambutol, sulfonamides (or trimethoprim-sulfamethoxazole), erythromycin, and streptomycin are the drugs most active against isolates of the M. terrae complex, and therapy with some combination of these agents plus surgical debridement offers the best current treatment of this disease. This study supports the contention arising from previous case reports of pulmonary disease that M. nonchromogenicum is the pathogenic member of the M. terrae complex.

Mycobacterium terrae tenosynovitis

A 72-year-old man was admitted with tenosynovitis of the left forearm and hand. Histopathologic examination of the excised tissue showed noncaseating granulomas. Mycobacterial culture produced Mycobacterium terrae complex. M. terrae infection of any site is rare. Analysis of four documented cases and our present case indicates that this organism causes infection in the forearm and hand after probable direct inoculation. It has not disseminated systemically from the site of local infection and may infect otherwise healthy hosts.

The tween opacity test as an aid in classification of mycobacteria.

The Tween opacity test can be used to differentiate (1) Mycobacterium flavescens from Mycobacterium gordonae and Mycobacterium szulgai, and (2) nonphotochromogenic strains of Mycobacterium kansaii from strains of the Mycobacterium terrae complex.